An inverter-integrated electric compressor is used as a compressor for an air conditioner installed in an electric car or a hybrid car. The inverter-integrated electric compressor has a configuration in which an inverter box, in which an inverter device that converts direct-current power from a power source into alternating-current power and applies it to the motor is mounted, is provided on an outer periphery of a housing accommodating a compressor and a motor. The rotational speed is variably controlled according to control signals transmitted from a vehicle-side control device (ECU).
The inverter device is formed of an inverter circuit, which is composed of power devices, such as power semiconductor devices (for example, IGBTs), that convert direct-current power into alternating-current power and apply it to a motor, and a control board, on which is mounted a control circuit including a microcomputer that controls alternating-current power to be applied to the motor according to the control signals from the ECU; and a noise-removing filter circuit, which is provided in a wiring path for supplying direct-current power to the power device. This noise-removing filter circuit is typically composed of high-voltage components, such as a head capacitor (smoothing capacitor), an inductor coil, a common mode coil, and the like.
Furthermore, there is a known inverter-integrated electric compressor in which an intelligent power module (Intelligent Power Module; IPM), in which a driving circuit (gate driver) and a self-protection function are integrally mounted, is used as a power-controlling power device constituting an inverter circuit (for example, see PTLs 1 and 2).